feat: Rain mapping

Assets/_Content/Materials/M_Env.mat

@@ -20,7 +20,7 @@ Material:
   m_CorrespondingSourceObject: {fileID: 0}
   m_PrefabInstance: {fileID: 0}
   m_PrefabAsset: {fileID: 0}
-  m_Name: M_Rain_Env
+  m_Name: M_Env
   m_Shader: {fileID: -6465566751694194690, guid: 8568d1cbfba747144b370a89c97e5011, type: 3}
   m_Parent: {fileID: 0}
   m_ModifiedSerializedProperties: 0
@@ -54,10 +54,12 @@ Material:
     - _Metallic: 0
     - _QueueControl: 0
     - _QueueOffset: 0
+    - _RainSize: 4
     - _Ripples: 1
+    - _RipplesSize: 3
     - _Smoothness: 0
     - _Wet: 1
     m_Colors:
-    - _Color: {r: 0.5849056, g: 0.5849056, b: 0.5849056, a: 1}
+    - _Color: {r: 0.49056602, g: 0.49056602, b: 0.49056602, a: 1}
   m_BuildTextureStacks: []
   m_AllowLocking: 1

Assets/_Content/Materials/M_Env.mat.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 747e7244c2ce24744ac7d2133efe6dd3
+guid: 74ee495a78c442345b0c5d5ae802e306
 NativeFormatImporter:
   externalObjects: {}
   mainObjectFileID: 2100000

Assets/_Content/Materials/M_Object.mat

@@ -20,11 +20,12 @@ Material:
   m_CorrespondingSourceObject: {fileID: 0}
   m_PrefabInstance: {fileID: 0}
   m_PrefabAsset: {fileID: 0}
-  m_Name: M_Rain_Object
+  m_Name: M_Object
   m_Shader: {fileID: -6465566751694194690, guid: 8568d1cbfba747144b370a89c97e5011, type: 3}
   m_Parent: {fileID: 0}
   m_ModifiedSerializedProperties: 0
-  m_ValidKeywords: []
+  m_ValidKeywords:
+  - _RAINMAPPING_UV
   m_InvalidKeywords: []
   m_LightmapFlags: 2
   m_EnableInstancingVariants: 0
@@ -54,7 +55,11 @@ Material:
     - _Metallic: 0
     - _QueueControl: 0
     - _QueueOffset: 0
+    - _RAINMAPPING: 1
+    - _RAINTYPE: 0
+    - _RainSize: 0.4
     - _Ripples: 1
+    - _RipplesSize: 0.55
     - _Smoothness: 0
     - _Wet: 1
     m_Colors: